Integrated environmental control and buffer air system

Abstract

An environmental control system for an aircraft includes a higher pressure tap associated with a higher compression location in a main compressor section. The higher pressure tap leads into a turbine section of a turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive a compressor section of the turbocompressor. A combined outlet receives airflow from a turbine outlet and a compressor outlet intermixing airflow and passing the mixed airflow downstream to be delivered to an aircraft system. A buffer air outlet communicates airflow to an engine buffer air system.

What is claimed is: 
     
       1. An environmental control system for an aircraft comprising:
 a higher pressure tap to be associated with a higher pressure location in a main compressor section associated with an aircraft engine, and a lower pressure tap to be associated with a lower pressure location in the main compressor section associated with the aircraft engine, said lower pressure location being at a lower pressure than said higher pressure location; 
 the lower pressure tap communicating to a first passage leading to a combined outlet, and having a second passage leading into a compressor section of a turbocompressor; 
 the higher pressure tap leading into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive the compressor section of the turbocompressor; 
 a turbine outlet receiving an exhausted turbine airflow exhausted from the turbine section; 
 a compressor outlet receiving an exhausted compressor airflow exhausted from the compressor section; 
 the combined outlet receiving the exhausted turbine airflow from the turbine outlet and the exhausted compressor airflow from the compressor outlet, intermixing the exhausted turbine airflow and the exhausted compressor to form a mixed airflow, and passing the mixed airflow downstream to be delivered to an aircraft; and 
 a buffer air outlet communicating a buffer airflow to an engine buffer air system, the buffer air outlet in communication with air from the turbocompressor, 
 wherein the turbocompressor includes a housing supporting the compressor section and the buffer air outlet is within the housing. 
 
     
     
       2. The environmental control system as set forth in  claim 1 , wherein the buffer air outlet is within the housing and downstream of the compressor outlet. 
     
     
       3. The environmental control system as set forth in  claim 1 , including a check valve controlling a bypass airflow from the lower pressure tap through the first passage between the lower pressure tap and the combined outlet. 
     
     
       4. The environmental control system as set forth in  claim 3 , wherein a first control valve is positioned on the higher pressure tap and is operable to control operation of the turbocompressor, wherein when the first control valve is in an open position, a low pressure airflow is drawn into the compressor section of the turbocompressor from the lower pressure tap, and when the first control valve is in a closed position, the low pressure airflow is not drawn through the compressor section of the turbocompressor and passes through the first passage. 
     
     
       5. The environmental control system as set forth in  claim 4 , including a second control valve controlling a common conduit airflow to the aircraft. 
     
     
       6. The environmental control system as set forth in  claim 5 , wherein the second control valve is positioned downstream of a second location at which the first passage and the combined outlet intermix into a common conduit. 
     
     
       7. The environmental control system as set forth in  claim 6 , including a heat exchanger within the common conduit after the second control valve, the heat exchanger cooling the common conduit airflow through the common conduit. 
     
     
       8. A gas turbine engine comprising:
 a fan section delivering air into a main compressor section where the air is compressed and communicated to a combustion section where the air is mixed with fuel and ignited to generate a high energy flow that is expanded through a turbine section that drives the fan and main compressor section; and 
 an environmental control system including:
 a higher pressure tap to be associated with a higher compression location in the main compressor section, and a lower pressure tap to be associated with a lower pressure location in the main compressor section, said lower pressure location being at a lower pressure than said higher pressure location; 
 the lower pressure tap communicating to a first passage leading to a combined outlet, and having a second passage leading into a compressor section of a turbocompressor; 
 the higher pressure tap leading into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section of the turbocompressor to in turn drive the compressor section of the turbocompressor; 
 a turbine outlet receiving airflow exhausted from the turbine section of the turbocompressor; 
 a compressor outlet receiving airflow exhausted from the compressor section of the turbocompressor; 
 the combined outlet receiving the airflows from the turbine outlet and the compressor outlet, intermixing the airflows from the turbine outlet and the compressor outlet to form a mixed airflow, and passing the mixed airflow downstream to be delivered to an aircraft; and 
 a buffer air outlet communicating a buffer airflow to an engine buffer air system, the buffer air outlet receiving air from the turbocompressor, 
 wherein the turbocompressor includes a housing supporting the compressor section of the turbocompressor and the buffer air outlet is within the housing. 
 
 
     
     
       9. The gas turbine engine as set forth in  claim 8 , wherein the buffer air outlet is within the housing and downstream of the compressor section of the turbocompressor. 
     
     
       10. The gas turbine engine as set forth in  claim 9 , including a check valve controlling a low pressure airflow from the lower pressure tap through the first passage between the lower pressure tap and the combined outlet. 
     
     
       11. The gas turbine engine as set forth in  claim 10 , wherein a first control valve is positioned on the higher pressure tap and is operable to control operation of the turbocompressor, wherein when the first control valve is in an open position, the low pressure airflow is drawn into the compressor section of the turbocompressor from the lower pressure tap, and when the first control valve is in a closed position, the low pressure airflow is not drawn through the compressor section of the turbocompressor and passes through the first passage. 
     
     
       12. The gas turbine engine as set forth in  claim 11 , including a second control valve operable to control a common conduit airflow to the aircraft. 
     
     
       13. The gas turbine engine as set forth in  claim 12 , wherein the second control valve is positioned downstream of a location at which the first passage and the combined outlet intermix into a common conduit. 
     
     
       14. The gas turbine engine as set forth in  claim 13 , including a heat exchanger within the combined conduit after the second control valve, the heat exchanger cooling the common conduit airflow through the common conduit. 
     
     
       15. An environmental control system for an aircraft comprising:
 a higher pressure tap to be associated with a higher compression location in a main compressor section associated with an aircraft engine, and a lower pressure tap to be associated with a lower pressure location in the main compressor section associated with the aircraft engine, said lower pressure location being at a lower pressure than said higher pressure location; 
 the lower pressure tap communicating to a first passage leading to a combined outlet, and having a second passage leading into a compressor section of a turbocompressor; 
 the higher pressure tap leading into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive the compressor section of the turbocompressor; 
 a turbine outlet receiving an exhausted turbine airflow exhausted from the turbine section; 
 a compressor outlet receiving an exhausted compressor airflow exhausted from the compressor section; 
 the combined outlet receiving the exhausted turbine airflow from the turbine outlet and the exhausted compressor airflow from the compressor outlet, intermixing into a mixed airflow, and passing the mixed airflow downstream to be delivered to an aircraft; 
 a housing supporting the compressor section and a buffer air outlet is within the housing, the buffer air outlet communicating a buffer airflow to an engine buffer air system; 
 a check valve controlling a bypass airflow from the lower pressure tap through the first passage between the lower pressure tap and the combined outlet; 
 a first control valve positioned on the higher pressure tap and is operable to control operation of the turbocompressor, wherein when the first control valve is in an open position, a low pressure airflow is drawn into the compressor section of the turbocompressor from the lower pressure tap, and when the first control valve is in a closed position, the lower pressure airflow is not drawn through the compressor section of the turbocompressor and passes through the first passage; and 
 a second control valve positioned downstream of a location at which the first passage and the combined outlet intermix into a common conduit operable to control airflow through the common conduit to an aircraft system.